In manufacturing parts from sheet metal, a metal forming press forms a flat sheet of metal positioned between upper and lower platens. The upper platen carries an upper die and is closed toward a lower die carried by the lower platen wherein certain portions of the sheet are cut, bent, drawn, or pierced by different features of the dies. Sometimes, separate press-mounted devices form other portions of the sheet along a direction different from the closing direction of the press. Accordingly, press-driven tool actuators convert press closing motion into transverse tool motion, and typically include mechanically or hydraulically actuated “cams.”
Mechanically actuated cams include an adapter body mounted to the upper platen or a die, a slider mounted on the adapter body to drive a tool affixed thereto, and a driver mounted on the lower platen or die. When the slider engages the driver, the press closing motion creates a camming action to drive the slider in a direction transverse to the press closing motion. But such devices are bulky, and require highly precise component alignment.
Hydraulically actuated “cams” include a tool actuator mounted on the lower platen for carrying and actuating a tool, and a pump mounted on the lower platen for converting mechanical power from the closing upper platen into fluid power for delivery to the tool actuator. The tool actuator includes a housing fastened to the lower platen, and a hydraulic cylinder and piston carried centrally by the housing for advancing an actuator plate. Separate guide rods are slidably carried through the housing outboard of the hydraulic piston and are attached at one end to the actuator plate and at another end to a return plate. Likewise, gas springs are carried by the housing outboard of the hydraulic piston and impose a force on the return plate for retracting the actuator plate via the guide rods. Although such devices are simpler and more flexible than the mechanical cams, they can be too bulky for certain small space applications.